RFR: 8214785: Remove unused WeakHandleType::vm_string

[coleen.phillimore at oracle.com]

Also looks good (and trivial).  I have this change in some private repo 
of mine.
thanks,
Coleen

On 12/4/18 8:03 AM, Per Liden wrote:
> The enum WeakHandleType::vm_string is never used and can be removed. 
> The StringTable uses WeakHandleType::vm_string_table_data.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8214785
> Webrev: http://cr.openjdk.java.net/~pliden/8214785/webrev.0
>
> /Per